Plasmid #4 serves as a control; it encodes the CL7 model (CL7M) protein, which directly binds the Im7 protein immobilized on the Im7 Resin.
Transcription is driven by the T7 RNA polymerase, and the plasmid is designed for expression in E. Coli.
For this plasmid, the target protein serves as the tag and binds directly to Im7.
A SUMO domain is fused to the C-terminus of the CL7 protein.
A Trx tag is upstream of the CL7 protein.